Many researchers and chemists require to carry out parallel chemical reactions on a new material or product under identical conditions of temperature and pressure. Frequently such reactions are carried out on small (5 to 50 ml) samples with a variety of gases in a pressurised reaction vessel.
In the past, such work has been carried out in high pressure reaction vessels, containing a single sample, the reaction vessel being sealed prior to being placed in an autoclave. Frequently repeat tests are required on a number of samples under identical conditions of pressure and temperature, leading to problems due to the difficulty in accurately reproducing the same test conditions for each sample.
Accordingly, an object of the invention is to provide an apparatus enabling the carrying out of chemical reactions simultaneously on a number of samples under identical pressure conditions in order. Another object of the present invention is to provide an apparatus permitting the simultaneous secure fitment of closure plugs to a plurality of upwardly open reaction vessels without requiring the use of special tools.
Accordingly, the present invention provides an apparatus for carrying out chemical reactions simultaneously on a number of samples under identical pressure conditions, said apparatus comprising a plurality of upwardly open pressure vessels mounted on a lower plate and a plurality of vessel closure means mounted on an upper plate such that the plurality of vessel closure means can be applied to the plurality of pressure vessels simultaneously in order to hermetically seal said vessels, securing means being provided for securing the plurality of closure means to the plurality of vessels, and wherein each vessel closure means has a passage communicating the interior of an associated pressure vessel with a common manifold.
Preferably said securing means comprises at least one retaining post extending upwardly from said vessel support, said at least one post passing through at least one aperture in said common closure support, locking means being provided for locking said closure support onto said at least one retaining post. Preferably a plurality of retaining posts are provided on said vessel support and said locking means is mounted on said closure support and has a plurality of keyhole apertures therethrough corresponding to said retaining post receiving apertures in said closure support, each retaining post having a shoulder or narrowed neck adjacent the upper end thereof, said locking means being moveable between an unlocked position wherein larger portion of each keyhole slot is aligned with the corresponding aperture in said closure support such that said locating posts can freely pass through said apertures in said closure support and said larger portion of said keyhole slot and a locked position wherein said narrower portion of each keyhole slot engages said shoulder or narrowed neck portion of respective retaining post to lock said closure support onto said retaining posts.
Preferably said plurality of retaining posts are arranged on a circle centred on a central axis of said vessel support and said locking means comprises a locking ring mounted on said closure support for rotation between said locked and unlocked positions.
A safety valve may be provided communicating with said common manifold, said safety valve being movable between an open vent position wherein said manifold, and said plurality of vessels communicating therewith, are vented to the atmosphere and a closed position wherein said manifold and pressure vessels may be pressurised. Preferably said safety valve is associated with said locking ring such that said safety valve can only be moved from its open to its closed position when said locking ring is in its locked position and said locking ring can only be moved from its locked to its unlocked position when said safety valve is in its open position.
Preferably said common manifold communicates with a source of pressurised gas.
Preferably said plurality of pressure vessels are arranged on a circle centred on the central axis of said vessel support, said vessel support comprising a circular plate, said vessel support comprising a substantially circular plate having apertures therein for receiving a lower portion of each pressure vessel, said lower portion having a smaller diameter that the remainder of said vessel, a stepped portion of said vessel abutting the upper surface of said aperture, each vessel being secured into each respective aperture by means of locking means such as a circlip received in an annular slot in said lower portion of each vessel at a position below said vessel support when said vessel is placed therein.
At least one locating post may be provided, extending upwardly from said vessel support, said closure support having at least one aperture therein for receiving said at least one locating post, at least a portion of said at least one retaining post being threaded, at least one correspondingly threaded fastener being associated with said closure support such that said closure support can be guided and drawn down over at least one retaining post by means of said at least one threaded fastener. Preferably two retaining posts are provided at spaced locations on said vessel support.
Preferably each closure means comprises a closure plug adapted to fit into the open end of a respective pressure vessel in order to close said pressure vessel. Preferably an annular groove may be provided around the periphery of said plug to receive an elastomeric sealing xe2x80x98Oxe2x80x99 ring. Preferably each closure plug has a gas inlet bore therethrough having a threaded portion allowing a gas line to be secured thereto, said gas line communicating with said common manifold allowing pressurised gas to be supplied to each pressure vessel and said common manifold is connected to a source of high pressure gas, for example a pressurised gas cylinder.
Heating means may be provided for heating each pressure vessel, for example an oil or water bath in which said vessels are immersed or individual heating jackets or band heaters provided around each vessel, or, alternatively, the entire apparatus may be placed on a hot plate.
Where it is required to stir the samples in the vessels, a PTFE coated magnetic follower may be provided in each vessel and the entire apparatus placed on a magnetic stirrer.
According to a further aspect of the invention there is provided an apparatus for carrying out chemical reactions simultaneously on a number of samples under identical pressure conditions, said apparatus comprising a plurality of upwardly open cylindrical pressure vessels mounted on a lower plate, and a plurality of vessel closure plugs mounted on an upper plate, a plurality of retaining posts extending upwardly from said lower plate to pass through a plurality of corresponding retaining post receiving apertures in said upper plate when said plurality of closure plugs are inserted into said plurality of vessels, locking means being mounted on said upper plate, said locking means having a plurality of keyhole apertures therein corresponding to said retaining post receiving apertures in said upper plate each retaining post having a shoulder or narrowed neck adjacent the upper end thereof, said locking means being moveable between an unlocked position, wherein larger portion of each keyhole slot is aligned with the corresponding aperture in said closure support such that said locating posts can freely pass through said apertures in said closure support and said larger portion of said keyhole slot, and a locked position, wherein said narrower portion of each keyhole slot engages said shoulder or narrowed neck portion of respective retaining post to lock said closure support onto said retaining posts.
Preferably said plurality of pressure vessels and said retaining posts are arranged on respective circles centred on a central axis of said lower plate, said locking means comprising a locking ring mounted on said upper plate support for rotation about the central axis of said upper plate between said locked and unlocked positions.